The present invention relates to a vacuum cleaner structure, and more particularly to a beater brush structure for use in the vacuum cleaner capable of preventing a damage of the rotating parts thereof such as due to overheat, dust and the like, and also reducing noise and vibration thereof, efficiently.
Conventionally, a vacuum cleaner comprises, as shown in FIG. 1 which is a perspective view representing a general type vacuum cleaner, a main body 1 having a chamber for collecting dirt, a suction nozzle 4 for sucking air containing dirt therethrough, a flexible hose 2 connected to a connector of the main body 1, a handle or a pipe 3 connected to a connector of the suction nozzle 4, said hose 2 and said pipe 3 connected to each other and adapted for guiding the dirt, having sucked by the nozzle 4 from the surface being cleaned such as a carpet or the like, to the main body 1.
As shown in FIG. 2 which is an exploded perspective view representing the structure of the nozzle of the vacuum cleaner in accordance with the prior art, the suction nozzle 4 generally comprises a base 5, and a rotatable beater brush structure 6 rotatably mounted to the base 5 and adapted for agitating the surface being cleaned, such as a carpet or the like, for improved removal of dirt therefrom. A drive motor 8 is mounted on the base 5 at a back position spaced apart from the beater brush structure 6 for generating power for driving the beater brush structure 6, and a cog belt or timing belt 7 is disposed between the beater brush structure 6 to the drive motor 8 in order to connect them with each other so that the driving power is transmitted from the drive motor 8 to the beater brush structure 6.
The suction nozzle 4 is also provided with an air guider 9 for guiding the air including dirt having sucked by the nozzle 4, a spring 10 for controlling the height, a connector 11 rotatably mounted to the air guider 9 in order to be connected to a free end of the pipe 3 so that the air containing dirt having sucked by the nozzle 4 is guided to the pipe 3 thereby. A bumper 12 and an electric switch 13 are provided to the nozzle 4 for absorbing the outside shock and for switching the electric power for driving the drive motor 8, respectively. There is provided in the suction nozzle 4 an upper casing 14 mounted onto the base 5 in order to cover the enclosures enclosed in the casing provided by the upper casing 5 and the base 14, a switching button 15 connected to the switch 13 and adapted to be pushed by the operator for turning on switch 13, a cover 16 for covering the upper casing 14, and an electric cord 17 for supplying electric power from the outside power source to the drive motor 8 by way of the switch 13.
Among the above elements of the nozzle 4, the rotating beater brush 6 which is related to the present invention is generally provided with a helical brush strip having a plurality of brush elements or brush bundles and a helical beater strip having a plurality of rigid beater projections, both strips adapted for agitating the surface being cleaned such as a carpet, for improved removal of dirt therefrom.
A representative example of such a beater brush structure combined with a nozzle of vacuum cleaner is that disclosed in U.S. Pat. No. 4,429,430 of John B. Lyman which is referred to this invention in conjunction with the drawings, FIGS. 2 to 4.
As shown in the above-referenced drawings, the rotatable beater brush 6 is provided with a rotatable cylindrical dowel or roller 20. The roller 20 carries a plurality of helical undercut channels 21 and 21' formed on the circumferential surface thereof in order to each receive a brush strip 23 and a beater strip 24 therein. The brush strip 23 has a plurality of brush bundles 22 secured thereto and spaced apart from each other for agitating the surface being cleaned on rotation of the beater brush 6. Also, the beater strip 24 comprises a plurality of relatively rigid projections 25 which become engaged with the surface being cleaned on rotation of the beater brush 6. The undercut channels 21 and 21', the brush strip 23 and the beater strip 24, both strips 23 and 24 received in said undercut channels 21 and 21', are provided with complementary cross sections for retention of the strips 23 and 24 in the channels 21 and 21' against centrifugal forces developed in rotation of the roller 20 about the axis thereof, respectively.
Also, the beater brush roller 20 is generally manufactured of relatively high strength maple, a kind of gingko, and provided with a pair of rotating axles 27 and 27' inserted into fitting holes 26 and 26' provided at opposite ends thereof in order to project therefrom and support the rotation thereof. Each of the rotating axles 27 and 27' is provided with a knurled machined portion 27a, 27'a at a center thereof, respectively, so that the axles 27 and 27' are fixed to the roller 20 and prevented from moving with respect to the roller 20 by virtue of the knurled machined portions 27a and 27'a fitted into the fitting holes 26 and 26' of the opposite ends of the roller 20.
Also, the beater brush 6 comprises bearing mounts 30 and 30' each provided with an annular outturned string guard flange shoulder 31, 31' formed inwards from the circumferential periphery of a disc, a pair of radially projecting tabs 32,32' integrally formed on the opposite portions of the outer surface of the flange shoulders 31, 31' for holding the bearing mounts 30, 30' in place, and bearing housing portions 33, 33' inwardly provided at a center thereof. Each of the bearing mount 30, 30' has an oil-filled bronze sleeve bearing 40, 40' mounted into the bearing housing portion 33, 33' and slightly projecting from the front end of the housing portion 33, 33'.
Disposed between one bearing mount 30' and one end of the beater brush roller 20 is a support pulley 50.
On the other hand, a sprocket 60 and an edge brush assembly 80 are provided to the beater brush 6 as disposed between the other end of the roller 20 and the other bearing mount 30.
The sprocket 60 comprises a gear pulley 60' and a ring flange 70. the gear pulley 60' is provided with a first belt retainer flange 61 at a side circumferential surface thereof, a toothed array 62 formed on the circumferential surface thereof near the first flange 61 and adapted to be driven by the timing belt 7. The ring flange 70 is disposed between the other end of the roller 20 and the gear pulley 60', and provided with a second belt retainer flange 71 integrally outwardly formed with the circumferential surface thereof. Also, the gear pulley 60' has a reduced diamether cylindrical end 63 for receiving the ring flange 70 thereon in order to dispose the ring flange 70 at the axially opposite side of the toothed array 62 so as to cooperate with the toothed array. A pair of openings 64 are axially formed in the gear pulley 60' at opposite positions on the basis of the center opening thereof in order to engage with a pair of set screws 90 which are engaged with a pair of openings 28 formed on the other end of the roller 20.
The edge brush assembly 80 is provided outboard of the sprocket 60 and, as shown in FIG. 3, includes carrier provided with a plurality of brush tufts 82 and an integral beater bar 81. The assembly 81 is provided with a reduced diameter end portion 83 having double steps and adapted to be coaxially received within the gear pulley 60' of the sprocket 60. A pair of openings 84 are axially formed throughout the length of the edge brush assembly 80 for receiving the set screws 90. The set screws 90 engage with the openings 64 and 84 of the gear pulley 60' and the edge brush assembly 80, respectively, thereby accomplishing the abutting of the ring flange 70, the gear pulley 60' and the edge brush assembly 80 to the other end of the roller 20.
In accordance, the above beater brush 6 rotates by means of the drive power transmitted from the drive motor 8 to the toothed array 62 of the gear pulley 60' by way of the timing belt 7, thereby allowing the brush bundles 22 of the brush strip 23 and the rigid beater projections 25 of the beater strip 24 provided on the circumferential of the roller 20 to agitate the surface being cleaned, such as a carpet or the like, for improved removal of dirt therefrom.
Also, rotation of the edge brush assembly 80 accompanies the rotation of the roller 20 so that the brush tufts 82 and the integral beater bar 81 provided on the circumferential surface of the assembly 80 efficiently agitate the edge of the surface being cleaned, for improved removal of dirt.
However, the beater brush 6 has disadvantages in that it comprises the bearing mounts 30 and 30' at opposite ends thereof, which bearing mounts 30 and 30' are provided with the bearing housing portions 33 and 33' each including the oil-filled sleeve bearing 40, 40' projecting from the front end of the bearing housing portions 33, 33', and also the beater brush roller 20 rotates at relatively high speeds of about 5000-7000 rpm, so that an an overheat occurs at the coupling portions of the bearing housing portions 33 and 33' of the bearing mounts 30 and 30' at which the axles 27 and 27', mounted to opposite ends of the beater brush roller 20, engage with the oil-filled sleeve bearings 40 and 40' of the bearing housing portions 33 and 33'. In result, the oil filled in the sleeve bearings 40 and 40' becomes overheated, resulting in lowering the viscosity thereof, thereby causing the overheated oil to flow toward the outside through the sleeve bearings 40 and 40'. Therefore, the sleeve bearings 40 and 40' loses the oil therefrom, resulting in a failure to support the rotation of the axles 27 and 27' of the beater brush roller 20, thereby causing the using life of the beater brush 6 to be shortened. Furthermore, the beater brush 6 has no auxiliary structure for flowing the cooling air near the connecting portions of the bearing housing portions 33 and 33' so that the above disadvantage of overheating becomes aggravated.
Also, the beater brush 6 has another disadvantage in that it has gaps C between the support end 50 and the flange shoulder 31' of the bearing mount 30' and also between the edge brush assembly 80 and the flange shoulder 31 of the bearing mount 30, respectively, so that dirt easily enters the rotating portions of the axles 27 and 27' through the gaps C, resulting in disturbing the smooth rotation of the axles 27 and 27'. Also, the axles 27 and 27', each inserted into the opposite ends of the beater brush roller 20, often deviates from the concentricity with the roller 20 during the rotation thereof, thereby causing noise and vibration to occur from the beater brush 6 due to interference thereof with the other parts of the nozzle 4.